Featured Research

from universities, journals, and other organizations

Much of early methane rise can be attributed to spreading of northern peatlands

Date:
January 17, 2010
Source:
University of Helsinki
Summary:
The surprising increase in methane concentrations millennia ago, identified in continental glacier studies, has puzzled researchers for a long time. According to a strong theory, this would have resulted from the commencement of rice cultivation in East Asia. However, a study by researchers in Finland shows that the massive expanse of the northern peatlands occurred around 5000 years ago, coincident with rising atmospheric methane levels.

The surprising increase in methane concentrations millennia ago, identified in continental glacier studies, has puzzled researchers for a long time. According to a strong theory, this would have resulted from the commencement of rice cultivation in East Asia. However, a study conducted at the University of Helsinki's Department of Environmental Sciences and the Department of Geosciences and Geography shows that the massive expanse of the northern peatlands occurred around 5000 years ago, coincident with rising atmospheric methane levels.

Related Articles


After water vapour and carbon dioxide, methane is the most significant greenhouse gas, resulting in about one fifth of atmospheric warming caused by humans. Methane emissions are mainly created by peatlands, animal husbandry, rice cultivation, landfill sites, fossil fuel production and biomass combustion.

Northern peatlands are immense sources of methane, but previous studies have argued them to have been established almost immediately after the Ice Age ended. Consequently, they could not explain the increase of methane, dated to have commenced thousands of years later, since the methane emissions of peatlands decrease as they age.

William Ruddiman, Professor Emeritus in environmental sciences at the University of Virginia, has presented a widely published theory according to which humanity started to affect the climate thousands of years ago, not just since the start of the industrial revolution. According to the theory, rice cultivation, commenced in East Asia already over 5,000 years ago, caused the declining methane amounts to again increase, which contributed to preventing the next ice age.

The timeframe of the spread of peatlands matches the increase in methane levels

The new study, conducted under the supervision of Professor Atte Korhola, explains the emergence of the peatlands in the northern hemisphere, and their development history, in a new way. The researchers compiled an extensive radiocarbon dating database concerning the bottom peat in peatlands. Based on over 3,000 dates, their statistical and location information-based analysis, it was identified that the expansion of northern peatlands significantly accelerated about 5,000 years ago. At the same time, the methane content in the atmosphere started to increase.

Peatland expansion resulted in the emergence of millions of square kilometres of young peatlands of the mineretrophic fen type, and they puffed large amounts of methane gas in to the air as the organic matter rotted. According to the study, the early increase in methane levels was mainly caused by natural reasons, and human operations are not necessarily required to explain it.

The expansion of peatlands was triggered by the climate turning moister and cooler, which caused the groundwater levels to rise, while accelerating peat build-up and growth. A similar methane peak may also emerge in the future if precipitation in the arctic areas increases as forecasted.

The study was published last week in the Quaternary Science Reviews series, and the study was conducted by Atte Korhola, Professor; Meri Ruppel, M.A.; and the docents Minna Vδliranta, Tarmo Virtanen and Jan Weckstrφm from the University of Helsinki's Environmental Change Research Unit (ECRU) and Heikki Seppδ, Professor in the Department of Geosciences and Geography at the University of Helsinki.


Story Source:

The above story is based on materials provided by University of Helsinki. Note: Materials may be edited for content and length.


Journal Reference:

  1. Korhola et al. The importance of northern peatland expansion to the late-Holocene rise of atmospheric methane. Quaternary Science Reviews, 2010; DOI: 10.1016/j.quascirev.2009.12.010

Cite This Page:

University of Helsinki. "Much of early methane rise can be attributed to spreading of northern peatlands." ScienceDaily. ScienceDaily, 17 January 2010. <www.sciencedaily.com/releases/2010/01/100114081543.htm>.
University of Helsinki. (2010, January 17). Much of early methane rise can be attributed to spreading of northern peatlands. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2010/01/100114081543.htm
University of Helsinki. "Much of early methane rise can be attributed to spreading of northern peatlands." ScienceDaily. www.sciencedaily.com/releases/2010/01/100114081543.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Ice Is Melting Faster Than Ever

Antarctic Ice Is Melting Faster Than Ever

Newsy (Mar. 27, 2015) — A new study of nearly two decades of satellite data shows Antarctic ice shelves are losing more mass faster every year. Video provided by Newsy
Powered by NewsLook.com
Clean-Up Follows Deadly Weather in Okla.

Clean-Up Follows Deadly Weather in Okla.

AP (Mar. 26, 2015) — Gov. Mary Fallin has declared a state of emergency for 25 Oklahoma counties after powerful storms rumbled across the state causing one death, numerous injuries and widespread damage. (March 26) Video provided by AP
Powered by NewsLook.com
At Least Four Dead After Floods in Northern Chile

At Least Four Dead After Floods in Northern Chile

Reuters - News Video Online (Mar. 26, 2015) — At least four people have been killed by severe flooding in northern Chile after rains battered the Andes mountains and swept into communities below. Rob Muir reports. Video provided by Reuters
Powered by NewsLook.com
Oklahomans "devastated" By Tornado Damage

Oklahomans "devastated" By Tornado Damage

Reuters - US Online Video (Mar. 26, 2015) — Buildings and homes lay in ruins and a semi-truck gets flipped following a fierce tornado that left at least one person dead. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins